What Is A Strike

Well, what is it? According to the official 2026 MLB rules, a strike—in isolation, absent swings and foul tips—is called when "any part of the ball passes through any part of the strike zone." The strike zone is duly defined, in a long-winded and broadly unpunctuated phrase, as "that area over home plate the upper limit of which is a horizontal line at the midpoint between the top of the shoulders and the top of the uniform pants, and the lower level is a line at the hollow beneath the kneecap," which "shall be determined from the batter's stance as the batter is prepared to swing at a pitched ball." The definition, handed first to human umpires, is filled with human imprecision. Reasonable people may disagree on the exact location of the "hollow beneath the kneecap." How precisely middle is the "midpoint," often defined by fans as the letters on the jersey? Would a given batter's midpoint vary over the course of a season should they start adhering to high-waisted fashion trends? With the implementation of the Automated Ball-Strike (ABS) system, these ambiguities have been quashed. After a rigorous independent height-measuring process that shrunk batters across the league, ABS now shirks the minutia of calf-to-thigh proportions in favor of defining the top of the strike zone at precisely 53.5 percent of a hitter's height, and the bottom at 27 percent of the player's height. So, that's that. While a human umpire may use knees and torsos as reference points, a true strike is called when any part of the ball passes through any part of the strike zone, which is defined as the area over home plate within a range between 27 and 53.5 percent of the batter's height.